Method and apparatus for color correction and apparatus for applying color correction

ABSTRACT

A color correction device and method separates achromatic color from chromatic color and independently controls the color. Color interpolation is performed along the locus of the color change of an input signal by dividing a color space of the input signal into blocks to surely include the locus changing from black to white passing through a center part based on the locus (chromatic locus) changing from black to white surrounding a color region to be handled by an input image equipment and the locus (achromatic locus) changing from black to white passing through the center part of the color region to be handled by the input image equipment. An achromatic part present in the center part of the color space is separately handled from a chromatic part present in its peripheral part.

This application is the national phase under 35 U.S.C. §371 of prior PCTInternational Application No. PCT/JP96/03169, which has an Internationalfiling date of Oct. 29, 1996, which designated the United States ofAmerica, the entire contents of which are hereby incorporated byreference.

TECHNICAL FIELD

The present invention relates to a color correction device, a colorcorrection method and a color correction application device whichapplies the color correction method to control the color of the systemto handle color image equipment.

BACKGROUND ART

FIG. 25 is a block diagram of a conventional color conversion method anda color conversion device, as disclosed for example in JapaneseUnexamined Patent Publication No. 6-86059 and referred to herein as“conventional example 1.”

In FIG. 25, R1 denotes an input γ-correction part which performsγ-correction of R, G and B signals read by a scanner part, R2 denotes apre-processing part which generates the minimum signal L by judging themagnitude of the γ-corrected R, G and B signals, generates thedifferential signals X,Y between the input R, G and B signals and theminimum signal L, and generates the region selection signal S, R3denotes a color conversion parameter memory part which accumulates thecolor conversion parameter with the region selection signal S as theaddress, R4 denotes an achromatic output signal generation part whichgenerates the output signal P₁ corresponding to the achromatic inputbased on the minimum signal L, R5 denotes an interpolation operatingpart which generates the output P₂ by interpolating the space to beformed by the minimum signal L and the differential signals X,Y by thetriangular prismatic interpolation, R6 denotes a limit processing partwhich performs the limit processing by adding the outputs P₁, P₂, R7denotes an output γ-correction part which prepares the output signal Pthrough γ-correction of the limit-processed signal P₃, and the outputsignals P generated by the output γ-correction part R7 are the inkquantity control signal of Y (yellow), M (magenta), C (cyan), etc., andsupplied to the printer part after gradation processing in a systematicdither method by a dither processing part.

Conventional example 1 having the above-mentioned constitution isfurther explained as follows. The input γ-correction part R1 performsγ-correction of the signal read by a scanner part with linearreflectance using a look-up table method of R=G=B for the achromaticinput. The pre-processing part R2 judges the magnitude of R, G and Bsignals based on the input R, G and B signals, sets the region selectionsignal S, and generates the minimum signal L and the differentialsignals X,Y between the minimum signal L and the input R, G and Bsignals.

The differential signals are determined as follows.

if ((R≧G) & (G≧B)), S=0, L=B, X=R−L, Y=G−L

if ((G>R) & (R≧B)), S=1, L=B, X=G−L, Y=R−L

if ((G≧B) & (B>R)), S=2, L=R, X=G−L, Y=B−L

if ((B>G) & (G>R)), S=3, L=R, X=B−L, Y=G−L

if ((B>R) & (R≧G)), S=4, L=G, X=B−L, Y=R−L

if ((R≧B) & (B>G)), S=5, L=G, X=R−L, Y=B−L

The color conversion parameter memory part R3 is a memory with theregion selection signal S as the address input, and four colorconversion parameters a_(s0), a_(s1), a_(s2) and a_(s3) set for eachbelow-mentioned unit triangular prism are accumulated as a set. Theachromatic signal generation part R4 outputs P₁=R(=G=B) when R=G=B. Theachromatic signal generation part R4 comprises a through circuit whereP₁=L. The interpolation operating part R5 obtains the output P₂ byperforming interpolation of the triangular prism based on the minimumsignal L and the differential signals X,Y from the pre-processing partR2 and the color conversion parameters a_(si) read from the colorconversion parameter memory part R3.

Where the output value set at the apex (lattice point) of the triangularprism is T_(i) (T₀, T₁, T₂, T₃), the output value P₂ in the coordinate(L, X, Y) in the unit triangular prism is calculated by the followingformula, where the lattice point value on the L-axis (X=0, Y=0) is zero,and L, X and Y are assumed to be normalized to 0˜1.

P ₂ =T ₀ ·X+(T ₂ −T ₀)·L·X+T ₁ ·Y+(T ₃ −T ₁)·L·Y

The limit processing part R6 adds the output value P₁ to the outputvalue P₂, and outputs the output value P₃ through the over-flow andunder-flow processing. That means,

if (P₁+P₂>255), P₃=255

if (P₁+P₂>0), P₃=0

else P₃=P₁+P₂

The output γ-correction part R7 performs γ-correction so that thereflection is linear during printing to the linear reflection signal P₃.Correction is performed through table conversion.

FIG. 26 is a block diagram of APPARATUS FOR ADJUSTING HUE, CHROMINANCE,AND LUMINANCE OF A VIDEO SIGNAL USING MATRIX CIRCUITS disclosed in U.S.Pat. No. 5,333,070 and referred to herein as “conventional example 2.”In FIG. 26, Q1 denotes a Y/C separation circuit which separates a videosignal into a brightness signal Y and a color signal C, Q2 denotes adecode circuit which converts the brightness signal Y and the colorsignal C into three primary colors R, G and B, Q3, Q4 and Q5 denotematrices of 3-row×3-column which perform color correction, Q6 denotes anA/D converter which performs analog/digital conversion of thecolor-corrected signal, Q7 denotes a frame memory which stores thedigitized signal, Q8 denotes a ROM which performs γ-conversion, and Q9denotes a head of a printer. Q10 is a regulation circuit which regulatesthe coefficient to the matrix circuit Q4.

The operation of the above-mentioned constitution is explained asfollows. The operation of the matrix circuits Q3, Q4 and Q5 of3-row×3-column which perform color correction is closely related to thepresent invention. The matrix circuit Q3 converts the input signal fromthe RGB coordinate system to an S_(fy) coordinate system. The S_(fy)coordinate system is a coordinate system which includes the skin coloraxis S, the green color axis f, and the brightness axis Y. When thematrix circuit Q3 is Mn, the matrix Mn on the skin color C1 and thegreen color C2 can be determined as indicated in the following formula.$\begin{pmatrix}100 \\0 \\Y_{1}\end{pmatrix} = {{M_{n}\begin{pmatrix}R_{1} \\G_{1} \\B_{1}\end{pmatrix}} = {{M_{n}{C_{1}\begin{pmatrix}0 \\100 \\Y_{2}\end{pmatrix}}} = {{M_{n}\begin{pmatrix}R_{2} \\G_{2} \\B_{2}\end{pmatrix}} = {M_{n}C_{2}}}}}$

The matrix circuit Q4 performs the color regulation using S_(fy)coordinate system, and outputs the signal expressed by the S_(fy)coordinate system. When the matrix of the matrix circuit Q4 is Mh, Mhcan be expressed as follows. $M_{h} = \begin{pmatrix}h_{11} & h_{12} & 0 \\h_{21} & h_{22} & 0 \\h_{31} & h_{32} & 1\end{pmatrix}$

The third row of the matrix Mh is (0 0 1) because the brightness of theachromatic signal is not changed. When the third row of the matrix Mh is(0 0 1), the role of each matrix element is as follows.

h₁₁<1.0 Decrease the saturation of C₁.

h₁₁>1.0 Increase the saturation of C₁.

h₂₁<0 C₁−hue in f-axis direction

h₂₁>0 C₁+hue in f-axis direction

h₃₁<0 Decrease the brightness of C₁.

h₃₁>0 Increase the brightness of C₁.

h₁₂<0 C₂−hue in S-axis direction

h₁₂>0 C₂+hue in S-axis direction

h₂₂<1.0 Decrease the saturation of C₂.

h₂₂>1.0 Increase the brightness of C₁.

h₃₂<0 Increase the brightness of C₂.

h₃₂>0 Increase the brightness of C₂.

Taking into consideration the above-mentioned role, the coefficients ofthe matrix Mh are determined according to the instruction of theregulation circuit Q10. The matrix circuit Q5 converts the input signalfrom the S_(fy) coordinate system to the RGB coordinate system. Thematrix used here is the inverse matrix of the matrix Mn. Colorregulation by the matrix circuit is performed by successively performingthe processes by the matrix circuits Q3, Q4, Q5.

In the above-mentioned method and device for color conversion accordingto conventional example 1, the pre-processing part R2 judges themagnitude of the input R, G and B signals, and outputs the regionselection signal S in a fixed manner. The color conversion parametermemory part R3 outputs the parameter of the triangular prismcorresponding to the region selection signal S, and the interpolationoperating part R5 receives the parameter to perform interpolation. Thus,the conventional device has a disadvantage that highly accurate colorcorrection can not be performed for the signal which must change thetriangular prism to be processed though the magnitudes of the input R, Gand B signals are same.

The color can not be accurately converted to the gradation of the R, Gand B signals and their color mixture of yellow (Y), magenta (M), cyan(C) and gray (K) irrespective of the magnitude of the R, G and Bsignals. In addition, in conventional example 1, the input R, G and Bsignals are separated into the minimum signal L and the differentialsignals X, Y, and then, added to each other by the limit processing partR6. Thus, the over-flow and under-flow processing must be performedduring the addition, resulting in the disadvantage that smooth change ingradation is lost depending on whether or not the processing isperformed.

On the other hand, the above-mentioned color correction device inconventional example 2 uses the S_(fy) coordinate system with adisadvantage that the third row of the matrix can only be used under thefixed condition. At the same time, in conventional example 2, when thebrightness of the achromatic signal is changed, the third row of thematrix must be regulated, but no items related to its regulation aredisclosed. Conventional example 2 has another disadvantage of doublingthe processing load because the coordinate system is converted intoanother coordinate system, and finally returned to the originalcoordinate system. Moreover, in conventional example 2, color regulationis performed for the skin color C₁ and green color C₂, causing problemsin regulating other colors.

The present invention solves the disadvantages related to theabove-mentioned conventional examples, and provides a device and amethod for color correction which is capable of separating theachromatic color and the chromatic color, and controlling each colorindependently.

The present invention also provides a device and a method for colorcorrection which is capable of separating the chromatic color by the hueand gradation, and independently controlling each color.

The present invention further provides a color correction device whichis capable of preparing an output table to be controlled, and rapidlyperforming the proceeding using the prepared output table.

The present invention furthermore provides a color correctionapplication device which is capable of providing an environment foreasily correcting and regulating the color by changing the output table.

SUMMARY OF THE INVENTION

The color correction device, according to the present invention, forchanging and correcting an input signal to be inputted as image datafrom one signal coordinate system to another signal coordinate systemincludes: an input block judging means for judging the divided block ofinput space for the input signal system to which the input signalbelongs; an input block internal position calculating means forobtaining the position in the divided block judged by the input blockjudging means at which the input signal is located; an output tablereferring means for obtaining the value of each apex of the block in theoutput space corresponding to the divided block judged by the inputblock judging means by referring to an output table; and an outputsignal generating means for generating an output signal using the valueof each apex of the block of the output space obtained by the outputtable referring means and the internal position obtained by the inputblock internal position calculating means. The input block judging meansconstitutes the divided block where the input space is divided atdivision points of each locus of a plurality of chromatic colors presentin a peripheral part of the achromatic region and the color regionpresent in the center of the color region, and the gradation which isthe level in the lightness direction is separated for each locus, andthe block whose input signal is judged to be inside every plane of thedivided block is selected as the divided block.

The output table referring means is characterized in that a table wherethe scan value of each color patch corresponding to the number of thelocus division points numbered sequentially from black to white of eachlocus is the coordinate value of the input division point and thecolorimetered value of each color patch is prepared as the coordinatevalue of the output division point is provided as the output table, andthe color is regulated and controlled by changing and correcting eitherof the coordinate value of the input division point or the coordinatevalue of the output division point.

The input block judging means is characterized in that the block isdivided so as to surely include the locus changing from black to whitepassing through the center part of the color region based on thechromatic color locus changing from black to white surrounding the colorregion and the achromatic color locus changing from black to whitepassing through the center part of the color region.

The input block judging means is also characterized in that thetetrahedron including the division points on the achromatic color locuschanging from black to white passing through the center part of at leastone color region is the divided block.

The input block judging means is characterized in that the color regionis divided based on a plurality of chromatic color loci changing fromblack to white different in saturation level.

The input block judging means is characterized in that the color regionis divided based on a plurality of chromatic color loci changing fromblack to white different in saturation level, and every block to dividethe color region is a tetrahedron.

The input block judging means is characterized in that the color regionis divided based on a plurality of chromatic color loci changing fromblack to white different in hue level.

The input block judging means is characterized in that the block isdivided by a conical body with the input signal as the apex, and theinput block internal position calculating means is characterized in thatthe internal position is set based on the volume of the conical body,and the internal position is obtained from the ratio of the volume ofthe divided block to the diagonal volume.

The output table referring means is characterized in that a first outputtable for converting the signal to be converted where the input divisionpoint coordinate value comprises the device value and the outputdivision point coordinate value comprises the standard color space valueinto the signal of the standard color space, and a second output tablefor converting the signal converted to the standard color space valuewhere the input division point coordinate value comprises the standardcolor space value and the output division point coordinate valuecomprises the device value into the signal of the device color space areprovided as the output table, and the signal of a certain device can beconverted into the signal of another device through the standardizedcolor conversion using the first output table and through theindividualized color conversion using the second output table.

Concerning the color correction device related to another invention, thecolor correction device for changing and correcting the input signal tobe inputted as the image data from one signal coordinate system to theother signal coordinate system is characterized in that an input blockjudging means which divides the input space comprising the input signalsystem into the blocks comprising divided lattices with equal intervalsfor each component, divides each component of the input signal by thecommon divisor of each component, judges the divided block using theinteger part of the quotient, and outputs the judged block number andthe decimal part of the quotient, an output table referring means whichis provided with an output table for rapid processing to store thecoordinate value of each apex of the block of the output spacecorresponding to the block number, and obtains the coordinate value ofeach apex of the block of the output space corresponding to the blocknumber judged by the input block judging means, and an output signalgenerating means which obtains the output signal using the decimal partof the quotient to be outputted from the input block judging means andthe coordinate value to be outputted from the output table referringmeans are provided.

Concerning the color correction method of the present invention, thecolor correction method for changing and correcting the input signal tobe inputted as the image data from one signal coordinate system to theother signal coordinate system is characterized in that an input blockjudging process to judge to which divided block to divide the inputspace comprising the input signal system the input signal belongs, aninput block internal position calculating process to obtain at whichposition in the divided block judged by the input block judging processthe input signal is located, an output table referring process to obtainthe value of each apex of the block in the output space corresponding tothe divided block judged by the input block judging process by referringto the output table, and an output signal generating process to generatethe output signal using the value of each apex of the block of theoutput space obtained by the output table referring process and theinternal position obtained by the input block internal positioncalculating process are provided, and the input block judging processconstitutes the divided block where the input space is divided atdivision points of each locus of a plurality of chromatic colors presentin a peripheral part of the achromatic region and the color regionpresent in the center of the color region, and the gradation which isthe level in the lightness direction is separated for each locus, andthe block whose input signal is judged to be inside every plane of thedivided block is selected as the divided block.

The output table referring process is characterized in that the color isregulated and controlled by changing and correcting either of thecoordinate value of the input division point or the coordinate value ofthe output division point of an output table where the scan value ofeach color patch corresponding to the number of the locus division pointnumbered sequentially from black to white of each locus is thecoordinate value of the input division point and the colorimetered valueof each color patch is prepared as the coordinate value of the outputdivision point.

The input block judging process is characterized in that the block isdivided so as to surely include the locus changing from black to whitepassing through the center part of the color region based on thechromatic color locus changing from black to white surrounding the colorregion and the achromatic color locus changing from black to whitepassing through the center part of the color region.

The input block judging process is also characterized in that thetetrahedron including the division points on the achromatic color locuschanging from black to white passing through the center part of at leastone color region is the divided block.

The color correction application device is provided with an output tablepreparing device having a pre-regulation image indicating means forindicating the pre-regulation image, a table locus selecting means forselecting the locus of the achromatic color and the chromatic color ofthe image, a table division point selecting means for selecting thedivision points to be corrected and regulated among the division pointsof the locus selected by the table locus selecting means, an effectchecking image indicating means for obtaining the color region affectedby correction and regulation by obtaining the input coordinate valueincluded inside a plurality of input blocks to which the locus selectionvalue and the division point selection value to be selected by the tablelocus selecting means and the table division point selecting means, andfor indicating the image part belonging to each locus of the colorregion, a table data editing means for editing the coordinate value ofthe input division point and the coordinate value of the output divisionpoint in the output table in which the scan value of each color patchcorresponding to the number of the locus division points sequentiallynumbered from black to white of each locus on the color region is thecoordinate value of the input division point and the colorimetered valueof each color patch is the coordinate value of the output division pointalong the directions of lightness, saturation and hue corresponding tothe loci of the achromatic color and the chromatic color of the image, akeeping means for keeping the output table corrected and regulated bythe table data editing means, and a post-regulation image indicatingmeans for converting the pre-regulation image using the output tablecorrected and regulated by the table data editing means and to indicatethe post-regulation image, enabling preparation of the output table andcorrection and regulation of the color by changing the contents of theoutput table.

The color correction application device is also characterized in thatthe pre-regulation image indicating means and the post-regulation imageindicating means are arranged on output devices with different output.

The color correction application device is further characterized in thatthe pre-regulation image indicating means and the post-regulation imageindicating means are arranged on a plurality of output devices.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating embodiment 1 of the presentinvention;

FIG. 2 is a conceptual view used to explain a divided condition of thecolor space in embodiment 1 of the present invention;

FIG. 3 is a conceptual view used to explain a color region of an actualimage equipment in embodiment 1 of the present invention;

FIG. 4 is a flow-chart illustrating operation of the input block judgingmeans in embodiment 1 of the present invention;

FIG. 5 is a schematic view used to explain the block judgment inembodiment 1 of the present invention;

FIGS. 6A-6C are schematic views used to explain the definition oflightness, hue and saturation in embodiment 1 of the present invention;

FIG. 7 is a flow-chart illustrating the procedure for judging theinternal position in embodiment 1 of the present invention;

FIG. 8 is a schematic view used to explain the judgment of the internalposition in embodiment 1 of the present invention;

FIG. 9 is a mode view of the output table in embodiment 1 of the presentinvention;

FIG. 10 is a flowchart illustrating the procedure for preparing theoutput table in embodiment 1 of the present invention;

FIG. 11 is a flow-chart illustrating the procedure of the output tablereferring means in embodiment 1 of the present invention;

FIG. 12 is a schematic view used to demonstrate the relationship betweenthe internal position and the divided block in embodiment 1 of thepresent invention;

FIG. 13 is a conceptual view of the input block in embodiment 2 of thepresent invention;

FIG. 14 is a conceptual view of the input block in embodiment 3 of thepresent invention;

FIG. 15 is a conceptual view of the input block in embodiment 5 of thepresent invention;

FIG. 16 is a schematic view used to explain the judging block divisionin embodiment 6 of the present invention;

FIG. 17 is a flow-chart illustrating the procedure for preparing theoutput table on the image output device in embodiment 7 of the presentinvention;

FIG. 18 is a block diagram illustrating embodiment 8 of the presentinvention;

FIG. 19 is a block diagram illustrating embodiment 9 of the presentinvention;

FIG. 20 is a divided block of an output table for rapid processing inembodiment 9 of the present invention;

FIG. 21 is a constitution of the output table preparing device inembodiment 10 of the present invention;

FIG. 22 is an explanatory figure of the table coordinate value editingelement in embodiment 10 of the present invention;

FIG. 23 is an explanatory figure of the table coordinate value editingelement in embodiment 10 of the present invention;

FIG. 24 is a flow-chart illustrating the procedure for preparing andcorrecting the output table in embodiment 10 of the present invention;

FIG. 25 is a block diagram used to explain the method and the device forcolor conversion in the conventional example 1 (Japanese UnexaminedPatent Publication No. 6-86059); and

FIG. 26 is a block diagram used to explain the method and the device forcolor conversion in the conventional example 2 (U.S. Pat. No.5,333,070).

DETAILED DESCRIPTION

Embodiment 1

Embodiment 1 of the present invention is explained with reference to thedrawings. FIG. 1 is a block diagram illustrating the device and methodfor color correction according to embodiment 1 of the present invention.

In the figure, 1 denotes an input signal, which is a digitized imagesignal, such as R, G and B signals of a scanner, R, G and B signals of amonitor, R, G and B signals of CIE (Commission Internationale del'Eclairage), X, Y and Z signals of CIE, L, a and b signals of CIE.Reference numeral 2 denotes an input block judging means for judging theblock of divided space (an input space) for the input signal system towhich the input signal 1 belongs, 3 denotes an input block internalposition calculating means for obtaining the position in the blockjudged by the input block judging means 2 at which the input signal 1 islocated.

Reference numeral 4 denotes an output table referring means forobtaining the value of each apex of the block of the output spacecorresponding to the block judged by the input block judging means 2 byreferring to the output table, and 5 denotes an output signal generatingmeans for generating the output signal 6 using the value of each apex ofthe block of the output space obtained by the output table referringmeans 4 and the internal position obtained by the input block internalposition calculating means 3. An output signal 6 can be a digitizedimage signal depending on the contents of the output table, such as theR, G and B signals of the scanner, R, G and B signals of the monitor, C,M and Y signals of the printer, R, G and B signals of CIE, X, Y and Zsignals of CIE, and L, a and b signals of CIE.

The color correction device according to embodiment 1, having theabove-mentioned constitution, is explained in detail below, the inputblock judging means 2 being described first. Initially, the input blockwill be explained with reference to the illustration of the color spacedivision indicated in FIG. 2.

In general, no chromatic component (hue and gradation) is present inblack through white even when the color is expressed by any space, andthe color (red, green, blue, etc.) is distributed around the changinglocus. In FIG. 2, a bold line indicates the changing locus, free fromany chromatic component, in black through white. In the presentinvention, this locus is referred to as the achromatic locus. However,the locus is not necessarily a changing locus which is free from anychromatic component, and any locus is acceptable so long as it is alocus changing from black to white with colors distributed therearound.Various colors are distributed in the periphery, but the range of thecolor to be handled by the device is naturally limited when particularimage equipment is assumed.

FIG. 2 expresses a three-dimensional body formed by connecting theoutermost contour of every color to be handled, i.e., the color range.In this color range, a locus smoothly changing from black to white canbe considered for every color. For example, the locus is consideredwhere the color is progressively changed from black to slightly reddishblack, more reddish black, then, changed from red with only redcomponent to the direction of white, and changed into white throughreddish white. FIG. 2 describes each locus for red, yellow, green andcyan. In the present invention, all loci are referred to as thechromatic loci. Similar to the achromatic locus, the chromatic locus isnot necessarily true-reddish even in a case of the red locus, and anylocus may be acceptable so long as it is the locus of the color of thesimilar chromatic component (hue in this case) located on the outermostcontour of the color range.

FIG. 2 indicates the achromatic locus and a plurality of chromatic loci.Though each locus is continuous, in the present invention, each locus isdivided into m sections (m≧2) so that the locus is expressed by (m+1)division points. In any locus, 0-th section denotes black, and m-thsection denotes white. In an example in FIG. 2, red n and red n+1 denotetwo adjacent division points in the red locus.

In embodiment 1, a block for dividing the color space comprises sixtotal division points including two adjacent division points of theachromatic locus, and adjacent division points for each of two adjacentchromatic loci on the hue. In FIG. 2, a pentahedron having apexes of(gray n, gray n+1, red n, red n+1, yellow n, and yellow n+1) indicatesthe divided block. In a case of n=0 and m−1, the divided block is atetrahedron. In the present invention, gradation of each locus can behandled separately to express each locus at the division points.

FIG. 3 indicates the color range, the achromatic locus and the chromaticlocus of an actual image equipment. Similarly in this case, a block fordividing the color space comprises six total division points includingtwo adjacent division points of the achromatic locus, and adjacentdivision points for each of two adjacent chromatic loci on the hue.Thus, a pentahedron having apexes of (gray n, gray n+1, red n, red n+1,yellow n, and yellow n+1) indicates the divided block.

Next, the input block judging function performed by the input blockjudging means 2 is explained with reference to the flow-chart of FIG. 4and the illustration of FIG. 5. First, the divided block is selected(step 20 indicated in FIG. 4). As explained in FIG. 2 and FIG. 3, thecolor space is divided into a plurality of blocks. In the selection ofthe divided block (step 20 indicated in FIG. 4), the coordinate systemof the input signal 1 is divided into a plurality of blocks, one ofwhich is selected. In the selection of the plane comprising the block(step 21 indicated in FIG. 4), the plane of the divided block of apentahedron or a tetrahedron is selected.

Next, judgment is made as to whether or not the input signal is insideevery plane (step 22 indicated in FIG. 4). FIG. 5 is a drawing whichwill be used to explain this judging method. In FIG. 5, judgment is madeas to whether the input signal S is located inside or outside thethree-dimensional body relative to the plane (red n, yellow n, and grayn) comprising the pentahedron, where the input signal 1 is S(hereinafter, the input signal 1 indicates the same signal as the inputsignal S). This can be determined by the positive/negative sign of thevolume of the three-dimensional body comprising the plane (red n, yellown, and gray n) and the input signal S. This operation is performed forevery plane of the selected divided block to judge whether the inputsignal S is located inside.

When it is judged that the input signal is not inside, the processreturns to the divided block selection (step 20 indicated in FIG. 4), tothereby select the next block to perform the same function. When it isjudged that the input signal is inside, the process advances to thejudged block selection (step 23 indicated in FIG. 4). The judged blockis the divided block containing the input signal S, and the dividedblock number is set as the judged block number.

Next, the input block internal position calculating means 3 will beexplained. First, the definition of lightness, hue and saturation usedin the present invention is explained with reference to FIGS. 6A-6C.Though lightness, hue and saturation are defined in the colorengineering aspect, the terms are defined in relation to the block todivide the color space in the present invention.

The lightness direction is defined as the direction of (red n−red n+1),(yellow n−yellow n+1), and (gray n−gray n+1) as indicated in FIG. 6A.The hue direction is defined as the direction of (red n−yellow n), and(red n+1−yellow n+1) as indicated in FIG. 6B. The saturation directionis defined as the direction of (gray n−red n), (gray n−yellow n), (grayn+1−red n+1), and (gray n+1−yellow n+1) as indicated in FIG. 6C. Otherblocks are similarly defined.

These definitions are appropriate in scanning the color space withoutany clearance though they are different from general definitions. Thisis because yellow n and yellow n+1 are different in lightness, hue andsaturation in the general definition. Thus, in the image equipmentdesigned so that the color is changed from yellow n to yellow n+1, thelightness, hue and saturation in the general definition must be handledsimultaneously to trace the change in color from yellow n to yellow n+1,but only the lightness direction may be handled in the definition oflightness, hue and saturation in the present invention. The same effectis expected in the hue direction and the saturation direction. Thedefinition in the present invention is thus appropriate for thecharacteristics of realistic image equipment.

Judgment of the internal position by the input block internal positionjudging means 3 is described by referring to the flow-chart of FIG. 7and the illustration of FIG. 8. First, internal position setting in thelightness direction is performed as follows.

The distance in the lightness direction is reduced (step 31 indicated inFIG. 7), thereby reducing the volume of the block by reducing thedistance in the lightness direction as indicated in FIG. 8. FIG. 8indicates the pentahedron in which the pentahedron surrounded by thetwo-dot chain line is narrowed. Then, judgment is made whether or notthe input signal S is inside every plane (step 32 indicated in FIG. 7).This is the judgment of whether the input signal S is inside the blockrelative to every plane of the pentahedron narrowed in the lightnessdirection as indicated in FIG. 8. Judgment is made in accordance withthe judgment whether the input signal is inside every plane by the inputblock judging means 2 (step 22 indicated in FIG. 2).

When it is judged that no input signal is inside relative to everyplane, the process advances to the narrowing direction changing process(step 34 indicated in FIG. 7). The direction to narrow the lightnessdirection is changed here. Then, the process returns to the process toreduce the distance in the lightness direction (step 31 indicated inFIG. 7).

When it is judged that the input signal is inside relative to everyplane, the procedure advances to the judgment process as to whether ornot the distance is minimum (step 33 indicated in FIG. 7). Here,judgment is made as to whether or not the distance in the narrowedlightness direction is not more than the prescribed minimum value. Whenthe distance is not a minimum, the procedure returns to the process toreduce the distance in the lightness direction in (step 31), and thedistance is further reduced to repeat the same operation. When thedistance is judged to be the minimum value or less, the position of theminimum distance in the lightness direction is relatively obtained, andthe obtained value is set to be the internal position in the lightnessdirection. Then, setting the internal position in the saturationdirection is initiated.

The operation is performed similarly to the internal position settingoperation in the lightness direction. What is different is the processto reduce the distance in the saturation direction (step 35 indicated inFIG. 7). This is the operation to reduce the distance in the directionof (gray n−red n), (gray n−yellow n), (gray n+1−red n+1) and (grayn+1−yellow n+1) which is the saturation direction as explained in FIG.8. When the distance is judged to be minimum or less in the judgmentprocess as to whether or not the distance is minimum (step 33 indicatedin FIG. 7), the position of the minimum distance in the saturationdirection is relatively obtained, and the obtained value is set as theinternal position in the saturation direction. Then, setting theinternal position in the hue direction is initiated.

The operation is performed similarly to the setting work of the internalposition in the lightness direction. What is different is the process toreduce the distance in the hue direction (step 35 indicated in FIG. 7).This is the operation to reduce the distance in the direction of (redn−yellow n), and (red n+1−yellow n+1) which is the hue direction asexplained in FIG. 8. When the distance is judged to be minimum or lessin the judgment process whether or not the distance is minimum (step33), the position of the minimum distance in the hue direction isrelatively obtained, and the obtained value is set as the internalposition in the hue direction.

The output table referring means 4 indicated in FIG. 1 is nextexplained, after the method to obtain the output table is explained.FIG. 9 illustrates the mode of the output table to be handled in thepresent invention. In FIG. 9, the division points number of the locus isthe number allotted to the achromatic locus and the chromatic locusindicated in FIG. 2 and FIG. 3, and the number of the division pointsfor each locus is the same. The coordinate value of the input divisionpoints is the value to express the color of the division points numberof the locus by the coordinate system of the input signal 1, and thecoordinate value of the output division points is the value of the colorof the division points number of the locus by the coordinate system ofthe output signal 6. The coordinate value of the input division pointsand the coordinate value of the output division points can be expressedby at least three color components, and in the illustration of FIG. 8,the coordinate values are expressed by three components, and may beexpressed by more components.

As indicated in FIG. 9, the output table is the coordinate value of theinput division points combined with the coordinate value of the outputdivision points corresponding thereto for each division point of thelocus. The coordinate value of the input division points is used by theinput block judging means 2 and the input block internal positioncalculating means 3, while the coordinate value of the output divisionpoints is used by the output table referring means 4.

The output table is prepared according to the procedure indicated inFIG. 10. FIG. 10 illustrates, for example, a procedure for preparing theoutput table of the scanner. First, the color patch preparation process(step 4000 indicated in FIG. 10) is performed. This process prepares thecolor patch along the locus which is smoothly changed from black towhite. For example, the color patch is prepared where the color ischanged progressively from black to slightly reddish black, and to morereddish black, to red with only red component, and then, in thedirection of white progressively, and changed to white through reddishwhite. This is the color patch of the red locus, and in addition, thecolor patches are prepared for the green, blue, yellow, magenta, andcyan loci and the achromatic color (gray) locus.

Next, the scanning process of the color patch (step 4001 indicated inFIG. 10) is performed. This operation is to scan each prepared colorpatch by the scanner and to obtain the scan signal. The scan signal isgenerally the R, G and B signals. Then, the color patch is colorimetered(step 4002 indicated in FIG. 10). This operation is to calorimeter theprepared color patch by the calorimeter. The colorimetered values areones in the X, Y and Z coordinate system and the L, a and b coordinatesystem.

The table preparation process (step 4003 indicated in FIG. 10) isperformed based on the data obtained in the above-mentioned procedures.The table is prepared with the scanned value of each color patch as thecoordinate value of the input division points and the colorimeteredvalue as the coordinate value of the output division points. Thedivision points of the locus are sequentially numbered from black towhite in each locus. The output table in the reverse relationship can beobtained by preparing the table with the colorimetered value of eachcolor patch as the coordinate value of the input division points and thescanned value as the coordinate value of the output division points.

When the color is regulated and controlled, it can be achieved bychanging and correcting the output table prepared in the above-mentionedmanner or the existing output table. For example, when the block togenerate the output signal is switched by changing the input block, thecoordinate value of the input division points corresponding to the inputblock to be regulated and controlled is changed and corrected. Thisincludes the case where the block which has been handled as the redblock signal is handled as the yellow block. In this case, the existingred block signal is handled as the yellow block, and the signal ishandled as the yellow block signal in the output generating means 5.

When the input block is not changed, but only the output signal ischanged, the coordinate value of the output division pointscorresponding to the input block to be regulated and controlled ischanged and corrected. This includes the case where the signal ishandled as the red block signal but the output signal is changed intoyellow. The existing red block signal is handled as the red blockwithout any change, but the output table to be referred to is changedinto yellow. As mentioned above, the color can be regulated andcontrolled by changing and correcting the output table.

The operation of the output table referring means 4 to obtain the valueof each apex of the output space corresponding to the block judged bythe input block judging means 2 by referring to the output tableprepared in the above-mentioned manner is described in detail byreferring to the flow-chart of FIG. 11. First, the block numberreferring process (step 40 indicated in FIG. 11) is performed. The blocknumber judged by the input block judging means 2 is referred to here.Second, the process for obtaining the division points of the achromaticlocus (step 41 indicated in FIG. 11) and the process for obtaining thedivision points of the chromatic locus (step 42 indicated in FIG. 11),and the process for obtaining the division points of two chromatic loci(step 43 indicated in FIG. 11) are performed. This operation obtains thedivision points of each apex comprising the block based on the referredblock number. More specifically, the operation is to obtain gray n andgray n+1 as the division points of the achromatic locus, red n and redn+1 as one division point of the chromatic locus, and yellow n andyellow n+1 as the two division points of the chromatic locusrespectively in the judgment block, described for example in FIG. 5.

Finally, the table referring process (step 44 indicated in FIG. 11) isperformed. The coordinate value of the output division points of thedivision points required by the below-mentioned output signal generatingmeans 5 is referred to based on the above-mentioned output table. Thereferred value is set as the value in the output coordinate system ofthe apex comprising the divided block containing the input signal 1.

The internal position obtained by the input block internal positioncalculating means 3 is defined as follows.

Internal position in the lightness direction: l

Internal position in the saturation direction: s

Internal position in the hue direction: h

The relationship of the internal position and the divided block isindicated in FIG. 12. When the coordinate values of the output divisionpoints of six apexes obtained by the output table referring means 4 areBk_(n), Bk_(n+1), Y_(n), Y_(n+1), R_(n), R_(m+1) (m=0˜n) (where, Bkdenotes gray, Y denotes yellow and R denotes red), the output signal 0can be obtained by the following formula where the output signal 6 to beoutputted from the output signal generating means 5 is expressed as 0.0 = (1 − s)[l × Bk_(n + 1) + (1 − l) × Bk_(n)] + s{h[l × Y_(n + 1)(1 − l) × Y_(n)] + (1 − h)[l × R_(n + 1) + (1 − l) × R_(n)]}

As mentioned above, in embodiment 1, the color can be separated andhandled for each block because the color space of the input signal 1 isdivided into a plurality of blocks where the achromatic color present inthe center of the color region, a plurality of chromatic colors presentin the periphery of the color region, and gradation which is the levelin their lightness direction are separated.

The table which is prepared with the scanned value of each color patchcorresponding to the division points number of the locus sequentiallynumbered from black to white of each locus as the coordinate value ofthe input division points and with the colorimetered value of each colorpatch as the coordinate value of the output division points is providedas the output table, and the color can be easily regulated andcontrolled by changing and correcting either of the coordinate value ofthe input division points or the coordinate value of the output divisionpoints.

In addition, the color space of the input signal 1 is divided into theblocks which surely contain the locus changing from black to whitepassing through the center part based on the locus (chromatic locus)changing from black to white surrounding the color region capable ofhandling the input image equipment and the locus (achromatic locus)changing from black to white passing through the center part of thecolor region capable of handling the input image equipment, and thecolor can be interpolated along the locus of the color change of theinput signal 1. Because the above-mentioned blocks are those around thelocus changing from black to white passing through the center part, theachromatic part present in the center of the color space can beseparated from the chromatic part present in the periphery thereof. Inaddition, each locus is expressed by the division points and gradationof each locus can be separated from each other.

Embodiment 2

Embodiment 2 is next described. As indicated in FIG. 2 and FIG. 3, theinput block in embodiment 1 is the block to divide the color space atsix total division points of two adjacent division points of theachromatic locus, and two adjacent division points for each of twochromatic loci on the hue. In embodiment 2, however, the input block isa tetrahedron of one of two types:

a) a tetrahedron comprising one division point on the achromatic locus,two adjacent division points on the chromatic locus, and one divisionpoint on the chromatic locus adjacent to said chromatic locus on thehue;

b) a tetrahedron comprising two division points on the achromatic locus,two adjacent division points on the chromatic locus, and one divisionpoint on the chromatic locus adjacent on the hue.

FIG. 13 is the conceptual view of the input block in embodiment 2. InFIG. 13, the tetrahedron of type a) is (gray n+1, red n, red n+1, yellown+1), and (gray n+1, red n, yellow n, yellow n+1), while the tetrahedronof type b) is (gray n, gray n+1, red n, yellow n).

The constitution of the color correction device according to embodiment2 is basically similar to that of embodiment 1 as indicated in FIG. 1.The difference is that the tetrahedron containing the division points onthe locus (the achromatic locus) changing from black to white passingthrough the center part of at least one color region is the dividedblock by the input block judging means 2 related to embodiment 2, andthe input block internal position calculating means 3, the output tablereferring means 4, and the output signal generating means 5 performsimilar processes to those of embodiment 1.

Thus, in embodiment 2, the block is the tetrahedron containing thedivision points on the locus (the achromatic locus) changing from blackto white passing through the center part of at least one color region,and every process can be equally handled, and the process is therebysimplified.

Embodiment 3

Embodiment 3 is next described. The input block in embodiment 1 is theblock to divide the color space at six total division points of twoadjacent division points of the achromatic locus, and two adjacentdivision points for each of two chromatic loci on the hue. In theembodiment 3, however, the locus of the color lower in the saturationlevel than the chromatic locus of embodiment 1 is added so that thelocus from the achromatic color to the chromatic color can be obtainedmore correctly.

FIG. 14 is a conceptual view of the input block in the embodiment 3. Theadded locus is the locus from black to white through yellow n′. This isequivalent to that the locus from gray n to yellow n through yellow n′is added as the locus in the saturation direction. The input block is ahexahedron, a pentahedron, and a tetrahedron with the division points ofeach locus as the apex.

That means, the constitution of the color correction device according toembodiment 3 is basically similar to that of embodiment 1 indicated inFIG. 1. The difference is that the color region is divided based on aplurality of loci (chromatic loci) changing from black to whitedifferent in saturation level by the input block judging means 2 relatedto the embodiment 3, and the input block internal position calculatingmeans 3, the output table referring means 4 and the output signalgenerating means 5 perform similar process to that of embodiment 1.

As mentioned above, in embodiment 3, a plurality of loci (chromaticloci) changing from black to white different in saturation level areprepared, the number of loci in the intermediate parts between theachromatic part located in the center part and the chromatic partlocated in the peripheral part is increased so that the locus from theachromatic color to the chromatic color can be obtained more correctly.

Embodiment 4

Embodiment 4 is next described. In the above-mentioned embodiment 2, theinput block is the tetrahedron containing the division points on atleast one achromatic locus, while in embodiment 3, a plurality ofchromatic loci different in saturation level are prepared, and the inputcolor space is divided by the hexahedron, the pentahedron and thetetrahedron.

That means, in embodiment 4, embodiment 2 is combined with embodiment 3,and a plurality of chromatic loci different in saturation level areprepared, and the tetrahedron with four division points of the locus asthe apexes is the input block.

The constitution of the color correction device according to embodiment4 is basically similar to that of the embodiment 1 indicated in FIG. 1.The difference is that the color region is divided based on a pluralityof loci (chromatic loci) changing from black to white and havingdifferent saturation levels by the input block judging means 2 relatedto the embodiment 4, and every input block is the tetrahedron, and theinput block internal position calculating means 3, the output tablereferring means 4 and the output signal generating means 5 performsimilar processes to those of embodiment 1.

As mentioned above, in embodiment 4, a plurality of loci (chromaticloci) changing from black to white different in saturation level areprepared, and every input block is the tetrahedron, every process can behandled equally, the processes are simplified, and the number of loci inthe intermediate parts between the achromatic part located in the centerpart and the chromatic part located in the peripheral part is increasedso that the locus from the achromatic color to the chromatic color canbe obtained more accurately.

Embodiment 5.

Embodiment 5 is next described. As indicated in FIG. 2 and FIG. 3, theinput block in embodiment 1 is the block to divide the color space atsix total division points of two adjacent division points of theachromatic locus, and two adjacent division points for each of twochromatic loci on the hue. In embodiment 5, however, the locus locatedbetween the chromatic loci of the embodiment 1 is added so that thelocus from one chromatic color to another chromatic color can beobtained more accurately.

FIG. 15 is a conceptual view of the input block in embodiment 5. Theadded locus is the locus from black to white through orange n. This isequivalent to that the locus from yellow n to red n through orange n isadded as the locus in the hue direction. The input block is thepentahedron or the tetrahedron with the division points of each locus asthe apexes.

The constitution of the color correction device according to embodiment5 is basically similar to that of embodiment 1 indicated in FIG. 1. Thedifference is that the color region is divided based on a plurality ofloci (chromatic loci) changing from black to white different insaturation level by the input block judging means 2 related to theembodiment 5, and the input block internal position calculating means 3,the output table referring means 4 and the output signal generatingmeans 5 perform similar processes to those of embodiment 1.

As mentioned above, in embodiment 5, a plurality of loci (chromaticloci) changing from black to white different in saturation level areprepared, and the number of loci of the chromatic part located in theperipheral part is increased so that the locus from one chromatic colorto another chromatic color can be obtained more correctly.

Embodiment 6

Embodiment 6 is next described. The input block internal positioncalculating means 3 of embodiment 1 calculates the divided block inwhich the input signal 1 is located by reducing the distance in thelightness, hue and saturation directions as indicated in FIG. 7, while,in embodiment 6, the judgment block is divided by the conical body withthe input signal 1 as the apex, and the internal position is set basedon the volume of the conical body. Thus, the calculation formula of theoutput signal generating means 5 is changed.

Embodiment 6 is explained in detail with reference to FIG. 16. Asindicated in FIG. 16, the input block judging means 2 divides thejudgment block into five conical bodies with the input signal 1 (symbolS) as the apex. The input block internal position calculating means 3sets the internal position based on the volume of the conical bodies,and the internal position is obtained from the ratio of the volume ofthe divided block to the diagonal volume. That means, the volume of eachconical body is obtained, and then, two conical bodies containing noline section connecting the input signal 1 to the concerned apex of thejudgment block are obtained for each apex of the judgment block. Forexample, the conical bodies to be selected for the apex (red n) are theconical body (S−red n+1, yellow n+1, gray n+1) and the conical body(S−yellow n, yellow n+1, gray n+1, gray n). Then, the volume of twoconical bodies selected for each apex is added thereto. This is referredto as the diagonal volume for each apex, and expressed by the symbols V(red n), V (yellow n), . . .

The internal position is obtained based on the following formula wherethe internal position is expressed by the symbols P (red n) and P(yellow n), and the volume of the judgment block is V (judgment block).

P(red n)=V(red n)/(2×V(judgment block))

P(yellow n)=V(yellow n)/(2×V(judgment block))

The output signal 6 is expressed as 0, and obtained by the followingformula. The formula means the internal interpolation with thevolumetric ratio. Bkn, Bkn+1, Yn, Yn+1, Rn, and Rn+1 are the coordinatevalues of the output division point corresponding to each apex of theselected block.0 = Bkn × P(gray  n) + Bkn + 1 × P(gray  n + 1) + Yn × P(yellow  n) + Yn + 1 × P(yellow  n + 1) + Rn × P(red  n) + Rn + 1 × P(red  n + 1)

As mentioned above, in embodiment 6, the judgment block is divided bythe conical bodies with the input signal 1 as the apex, and the internalposition is set based on the volume of the conical bodies, and theinternal position is obtained from the ratio of the volume of thejudgment block to the diagonal volume, and the output signal 6 can beeasily obtained using the coordinate value of the output division pointcorresponding to each apex of the polygon.

Embodiment 7

Embodiment 7 is next described. In embodiment 1, it is indicated thatthe output table is prepared by the procedure shown in FIG. 10, and inembodiment 7, the procedure for preparing the output table on the imageoutput device such as a monitor or a printer.

FIG. 17 indicates the procedure for preparing the output table on theimage output device. In preparing the color patch (step 4010 indicatedin FIG. 17), the color patch data to be displayed on the monitor or tobe printed by the printer is prepared. The data to be prepared is thedata for the achromatic locus and the data for the chromatic locuschanging from black to white in a plurality of stages. Then, thecolorimetry of the color patch (step 4011 indicated in FIG. 17) isperformed. The color to be displayed on the monitor or printed by theprinter is colorimetered using the prepared color patch data. Finally,the table is prepared (step 4012 indicated in FIG. 17). The table isprepared with the data value of each prepared color patch as thecoordinate value of the input division points and the coordinate valueof the output division points. The locus division points aresequentially numbered from black to white of each locus. The outputtable of the reverse relationship is obtained if the table is preparedwith the colorimetered value of each color patch as the coordinate valueof the input division points and the data value of each prepared colorpatch as the coordinate value of the output division points.

As mentioned above, in embodiment 7, the table on the image outputdevice is obtained because the table on the image output device isprepared, enabling the color correction including the image outputequipment.

Embodiment 8

Embodiment 8 is next described. Embodiment 8 is an example of convertingthe image signal of a certain device (scanner and monitor) into theimage signal of other devices (monitor and printer).

As for the constitution of the color correction device related toembodiment 8, in the constitution of embodiment 1 indicated in FIG. 1,the first output table to convert the converted signal in which thecoordinate value of the input division point is constituted by thedevice value, and the coordinate value of the output division point isconstituted by the standard color space value into the signal of thestandard color space, and the second output table to convert the signalconverted into the standard color space in which the coordinate value ofthe input division point is constituted by the standard color spacevalue and the coordinate value of the output division point isconstituted by the device value are provided as the output table to bereferred to by the output table referring means 4, and the signal of acertain device can be converted in the signal of the other devicethrough conversion of the standardized color using the first outputtable and through the conversion of the individualized color using thesecond output table.

FIG. 18 indicates the block diagram for embodiment 8. In the diagram, 7denotes the signal to be converted, for example, RGB signal of thescanner and the RGB signal of the monitor. Reference numeral 8 denotesthe standardized color conversion process to convert the convertedsignal 7 into the signal of the standard color space. The standard colorspace means the XYZ color space and the Lab color space of CIE.Reference numeral 9 denotes the individualized color conversion processfor converting the signal converted by the standardized color conversionprocess 8 into the signal of the device color space. The device colorspace means the space to be constituted by the signal of the device tohandle the image. The device color space is generally the RGB signalspace for the scanner, the RGB signal space for the monitor, and RGBsignal space or CMY (K) signal space for the printer. Reference numeral10 denotes the signal converted by the individualized color conversionprocess 9.

The standardized color conversion process 8 and the individualized colorconversion process 9 are explained in detail below. The output table tobe prepared by the standardized color conversion process 8 is the tablein which the coordinate value of the input division points isconstituted by the device value and the coordinate value of the outputdivision points is constituted by the standard color space value. Theconverted signal 7 is converted into the signal of the standard colorspace in accordance with the process indicated in the embodiment 1 usingthe output table. The output table to be prepared by the individualizedcolor conversion process 9 is the table in which the coordinate value ofthe input division points is constituted by the standard color spacevalue and the coordinate value of the output division points isconstituted by the device value. The signal of the standard color spaceis converted into the converting signal 10 in accordance with theprocess indicated in embodiment 1 using the output table.

In embodiment 8, the process indicated in embodiment 1 is performedtwice, and thus, the image signal of a certain device (scanner andmonitor) can be converted into the image signal of the other device(monitor and printer), and the color control of the system comprisingvarious image equipment can be performed.

Embodiment 9

Embodiment 9 is next described. Embodiment 9 is an example for rapidlyperforming the process described in embodiment 1. Prior to theexplanation of the rapid processing, the procedure for preparing theoutput table for rapid processing is explained.

The output table for rapid processing is the output table described inFIG. 9 converted into the lattice-shaped table. To begin with, thecommon divisor is obtained for each component of the input signal of theoutput table. For example, if the input signal is the RGB signal and thesignal of the space of each 8-bit, the common divisor is 15 or 17. Then,the input signal space is divided by each common divisor to form thelattice divided with equal intervals for each component. The dividedblock becomes parallelopiped in the input signal space. Then, the outputsignal 6 is obtained in the process indicated in embodiment 1 with thecoordinate value of every lattice point as the input signal 1, and theoutput table for rapid processing comprising the input signal 1 and thecorresponding output signal 6 is prepared.

FIG. 19 is the block diagram illustrating the color correction devicerelated to the embodiment 9. In FIG. 19, 1 denotes the input signalincluding the digitized image signal such as the R, G and B signals forthe scanner, the R, G and B signals for the monitor, the R, G and Bsignals for CIE, the X, Y and Z signals for CIE, and L, a and b signalsfor CIE. Reference numeral 12 denotes the input block judging means tojudge belonging to the block to divide the space (input space)comprising the input signal system. Reference numeral 14 denotes theoutput table referring means for obtaining the value of each apex of theblock of the output space corresponding to the block judged by the inputblock judging means 12 by referring to the output table for rapidprocessing. Reference numeral 15 denotes the output signal generatingmeans for generating the output signal using the value of each apex ofthe block of the output space obtained by the output table referringmeans 14 and the internal position obtained by the input block judgingmeans 12. Reference numeral 6 denotes the output signal. The outputsignal 6 can be the R, G and B signals for the scanner, the R, G and Bsignals for the monitor, C, M and Y signals for the printer, R, G and Bsignals for CIE, the X, Y and Z signals for CIE, and L, a and b signalsfor CIE according to the content of the output table.

The input block judging means 12 divides each component of the inputsignal 1 by the common divisor of each component. The block divided bythe above-mentioned lattice point is judged using the integer part ofthe quotient. The judged block number is transmitted to the output tablereferring means 14. The decimal part of the quotient is transmitted tothe output signal generating means 15. The decimal part of the quotientis expressed as k₀, k₁, and k₂. When the common divisor is the power oftwo, the shift calculation is performed, and the block can be judged andk₀, k₁, and k₂ corresponding to the decimal part of the quotient can beobtained at higher speed.

The output table referring means 14 obtains the coordinate value of eachapex of the block of the output space corresponding to the block numberjudged by the input block judging means 12 by referring to the outputtable for rapid processing. The obtained coordinate values are expressedas D_(n m o), D_(n+1 m o), D_(n m+1 o), D_(n m o+1), D_(n+1 m+1 o),D_(n+1 m o+1), D_(n m+1 o+1), D_(n+1 m+1 o+1). These coordinate valuesare indicated in FIG. 20.

The output signal generating means 15 obtains the output signal 6 usingthe decimal part k₀, k₁, and k₂ transmitted from the input block judgingmeans 12 and the coordinate values D_(n m o), D_(n+1 m o), D_(n m+1 o),D_(n m o+1), D_(n+1 m+1 o), D_(n+1 m o+1), D_(n m+1 o+1),D_(n+1 m+1 o+1) transmitted from the output table referring means 14.The output signal 6 (symbol 0) is obtained based on the followingformulae, where T_(ijk) indicates the intermediate data. Theintermediate data are obtained by the following formulae.

T _(n m o) =K ₀×(D _(n+1 m o) −D _(n m o)

Tnm _(o+1) =K ₀×(D _(n+1 m o+1) −D _(n m o+1))

T _(n m+1 o) =K ₀×(D _(n+1 m+1 o) −D _(n m+1 o))

T _(n m+1 o+1) =K ₀×(D _(n+1 m+1 o+1) −D _(n m+1 o+1))

In addition, the intermediate data obtained by the above formulae aresubstituted in the right side of the following formulae to obtain theintermediate data.

T _(n m o) =K ₁×(T _(n m+1 o) −T _(n m o))

T _(n m o+1) =K ₁×(T _(n m+1 o+1) −T _(n m o+1))

Then, the intermediate data obtained by the above formulae aresubstituted in the right side of the formula below to obtain the outputsignal 6.

O=K ₂×(T _(n m o+1) −T _(n m o))

As mentioned above, in embodiment 9, the table for rapidly processingcorresponding to the divided block comprising the lattices divided withequal intervals for each component of the input signal space is used,and the content to be processed of the input block judging means 12 issimplified, and the internal position is also obtained at the same time,and the processing speed can be increased by one digit compared withthat of embodiment 1.

Embodiment 10

Embodiment 10 is next described. Embodiment 10 is an example of thecolor correction application device for realizing each embodimentmentioned above.

FIG. 21 is a drawing used to explain the color correction applicationdevice having the output table preparing device related to theembodiment 10. In FIG. 21, A1 denotes the table locus selection elementfor selecting the achromatic locus and the chromatic locus changing fromwhite to black, A2 denotes a table division point selection element forselecting the locus selected by the table locus selection element A1, A3denotes the color indication element of the input division point to beindicated with the data of each input division coordinate point of thelocus selected by the table locus selection element A1, A4 denotes thecoordinate value indication and edition element of the input divisioncoordinate point capable of indicating and editing the data of the inputdivision coordinate point of the locus selected by the table locusselection element A1.

Reference numeral A5 denotes the color indication element of the outputdivision point for indicating the data of each output divisioncoordinate point of the locus selected by the table locus selectionelement A1 as the color, A6 denotes the coordinate value indication andedition element of the output division coordinate point capable ofindicating and editing the data of the output division coordinate pointof the locus selected by the table locus selection element A1, A7denotes the pre-regulation image indication element for indicating thepre-regulation image, A8 denotes the post-regulation image indicationelement for indicating the post-regulation image, A9 denotes the colorpick-up element for picking up the color from the pre-regulation imageindication element A7 and receiving/delivering the data to the colorindication element A3 of the input division point, A10 denotes the tablecoordinate value edition element for changing the color of thecoordinate value of the input division point or the color of thecoordinate value of the output division point, and A11 denotes theeffect checking image indication element for indicating the image partto be affected by the edited table coordinate value.

The table data editing means for editing the coordinate value of theinput division point and the coordinate value of the output divisionpoint of the output table in which the scanned value of each color patchcorresponding to the locus division point number which is numberedsequentially from black to white of each locus is the coordinate valueof the input division point and the colorimetered value of each colorpatch is the coordinate value of the output division point along thelightness direction, the saturation direction and the hue directioncorresponding to the achromatic locus and the chromatic locus of theimage comprises the color indication element A3 of the input divisionpoint, the coordinate value indication and edition element A4 of theinput division coordinate point, the color indication element A5 of theoutput division point, the coordinate value indication and editionelement A6 of the output division coordinate point, the color pick-upelement A9, and the table coordinate value edition element A10, and akeeping means not indicated in the drawing to keep the output tablewhich is prepared, corrected and regulated by the table data editingmeans is incorporated in the output table preparation device.

The details of each element are explained in detail below. The tablelocus selection element A1 selects the achromatic locus and thechromatic locus changing from white to black. In FIG. 21, buttons of Bk,R, G, B, C, M and Y are indicated, and as indicated in theabove-mentioned embodiments, the number of the table loci is not limitedto six. This number is determined according to the content of the table.Each button may be indicated with the color suitable for the color ofthe table locus. When the button is pressed, the color indicationelement A3 of the input division point, the coordinate value indicationand edition element A4 of the input division coordinate point, the colorindication element A5 of the output division point, and the coordinatevalue indication and edition element A6 of the output divisioncoordinate point are changed. The elements A3-A6 are initially set tothe table value of the locus selected by the table locus selectionelement A1.

The table division point selection element A2 instructs the divisionpoints to be corrected and regulated among the division points of thelocus selected by the table locus selection element A1. One or moretable division point selection elements A2 can be selected. When aplurality of elements are selected, correction and regulation areperformed so that the selected division points are connected by thesmooth curve. In addition, when the table division point selectionelement A2 is selected, the color region to be affected by correctionand regulation is obtained by obtaining the input coordinate valueincluded within a plurality of input blocks to which the locus selectionvalue and the division point selection value to be selected based on theinput division coordinate points of the selected division points, andthe image part belonging to the color region is indicated by the effectchecking image indication element A11.

The color indication element A3 of the input division point, thecoordinate value indication and edition element A4 of the input divisioncoordinate point, the color indication element A5 of the output divisionpoint, and the coordinate value indication and edition element A6 of theoutput division coordinate point respectively correct and regulate thetable data (coordinate value) of the input division points and theoutput division points. The coordinate value indication and editionelement directly changes the numerical values to correct and regulatethe table data (coordinate value) of the input division points and theoutput division points. The color indication element corrects andregulates the table data (coordinate value) of the input division pointsand the output division points watching the color. The color indicationelements and the coordinate value indication and edition elements of thesame division point are interlocked with each other, and when one iscorrected and regulated, the other is changed. Either of the inputdivision point or the output division point may be selected by selectingthe color indication element A3 of the input division point and thecolor indication element A5 of the output division point.

The pre-regulation image indication element A7 indicates the imagebefore regulation. Any image to be corrected and regulated may beacceptable, but in order to improve the workability, the natural imageor the image having the color pallet is used. The pre-regulation imageindication element A7 has the image data value referring function, andthe color data in the image can be directly seen by the numerical value.

The post-regulation image indication element A8 indicates the imageafter regulation. The image after regulation can be prepared byconverting the image in accordance with the above-mentioned embodimentusing the table corrected and regulated by the color indication elementA3 of the input division point, the coordinate value indication andedition element A4 of the input division coordinate point, the colorindication element A5 of the output division point, the coordinate valueindication and edition element A6 of the output division coordinatepoint, and the table coordinate value edition element A10. Thepost-regulation image indication element A8 has the image data valuereferring function, and the color data in the image can be directly seenby the numerical value.

The color pick-up element A9 picks up the color from the pre-regulationimage indication element A7 to receive/deliver the data. The picked-updata is delivered to the color indication element A3 of the inputdivision point, the coordinate value indication and edition element A4of the input division coordinate point, the color indication element A5of the output division point, and the coordinate value indication andedition element A6 of the output division coordinate point. The contentsof the color indication element and the coordinate value indicationedition element are changed following the delivered data.

The table coordinate value edition element A10 changes the color of thecoordinate value of the input division point or the color of thecoordinate value of the output division point using a tool. Though thecoordinate value is directly inputted or the color is directlydesignated by the color indication element A3 of the input divisionpoint, the coordinate value indication and edition element A4 of theinput division coordinate point, the color indication element A5 of theoutput division point, and the coordinate value indication and editionelement A6 of the output division coordinate point, the table coordinatevalue edition element A10 designates the color or the coordinate valueby more complicate method.

FIG. 21 shows the tool for changing the color of the coordinate value ofthe division point in the hue direction, the saturation direction andthe lightness direction in the present invention, and the tool to changethe color of the coordinate value of the division point by changing thecurve using a graph. FIG. 22 and FIG. 23 show the details of thesetools. FIG. 22 shows the tool for changing the color of the coordinatevalue of the division point in the hue direction, the saturationdirection and the lightness direction in the present invention. When thebutton (indicated by a conical body in the drawing) in the huedirection, the saturation direction and the lightness direction isdepressed, the table value is changed according to the kind of thebutton. For example, when the output division point of yellow n isselected using the table locus selection element A1, the table divisionpoint selection element A2, the color indication element A3 of the inputdivision point, and the color indication element A5 of the outputdivision point, the table value of the output division point of yellow nis changed along the line comprising the following output divisionpoints.

Hue direction: along the line to connect red n, yellow n, and green n

Saturation direction: along the line to connect gray n and yellow n

Lightness direction: along the line to connect yellow n−1, yellow n,yellow n+1.

FIG. 23 shows the tool for changing the color of the coordinate value ofthe division points by changing the curve using a graph. In FIG. 23, theoutput table is plotted on the a*b* plane of CIELAB. When the point P isedited, the point P is moved along the dotted line when the color ischanged in the hue direction, and along the one-dot chain line when thecolor is changed in the saturation direction. In the drawing, the pointP is moved on the a*b* plane, but in the present invention, the tablevalue is changed along the direction explained by the tool to change thecolor of the coordinate value of the division point in the huedirection, the saturation direction and the lightness direction. Inaddition, even when the point P is edited free from any restriction inthe hue direction, the saturation direction and the lightness direction,the table value is changed on the plane constituted by the line in thedirection explained by the tool to change the color of the coordinatevalue of the division point in the hue direction, the saturationdirection and the lightness direction.

The effect checking image indication element A11 indicates the imagepart to be affected by the edited table coordinate value. When the tabledivision point selection element A2 is selected, the color region to beaffected by correction and regulation is obtained based on the inputdivision coordinate point of the selected division point, and the imagepart belonging to the color region is indicated.

The operation of the output table preparing device A is next explainedreferring to FIG. 24. FIG. 24 indicates the procedure for preparing,correcting and regulating the output table using the output tablepreparing device A.

To begin with, pre-regulation image indication (sign a1 indicated inFIG. 24) is performed. The image to be regulated is indicated using thepre-regulation image indication element A7. Then, the locus selection(sign a2 indicated in FIG. 24) is performed. The locus is selected usingthe table locus selection element A1. Then, the division point selection(sign a3 indicated in FIG. 24) is performed. This is performed using thetable division point selection element A2.

Next, the region to be affected is checked (sign a4 indicated in FIG.24). When the locus selection (sign a2 indicated in FIG. 24) and thedivision point selection (sign a3 indicated in FIG. 24) is performed,the color region to be affected by correction and regulation is obtainedusing the locus selection value and the division point selection valuewithin the output table preparing device A. In the color region, theinput coordinate value included in a plurality of input blocks to whichthe locus selection value and the division point selection value belongcan be obtained in accordance with the above-mentioned embodiment. Then,the color region to be affected by correction and regulation can beindicated by the effect checking image indication element A11. Judgmentis made whether the color region is corrected and regulated by theindication. When it is not appropriate, the procedure returns to thelocus selection (sign a2 indicated in FIG. 24). When it is appropriate,the procedure advances to the following procedure.

In correction and regulation of the division points (sign a5 indicatedin FIG. 24), the color of the input division point, the coordinate valueof the input division coordinate point, the color of the output divisionpoint, and the coordinate value of the output division coordinate pointare corrected and regulated using various elements. When the coordinatevalue of the division point is directly corrected and regulated, it iscorrected and regulated using the coordinate value indication andedition element A4 of the input division coordinate point and thecoordinate value indication and edition element A6 of the outputdivision coordinate point.

When correction and regulation is performed watching the color of thedivision points, the color indication element A3 of the input divisionpoint and the color indication element A5 of the output division pointare used. The color pick-up element A9 picks up the color from thepre-regulation image to receive/deliver the data. More complicatedcorrection and regulation is performed using the table coordinate valueedition element A10. This is performed along the hue direction, thesaturation direction and the lightness direction in the presentinvention, or by changing the curve of the graph to be used.

When the output table is corrected and regulated using various elements,the pre-regulation image is converted in the procedure described in theabove-mentioned embodiment within the output table preparing device A.The converted image is indicated using the post-regulation imageindication element A8. Then, the post-regulation image judgment (sign a6indicated in FIG. 24) is performed. Judgment is made whether or not theindicated image is appropriate. When it is not appropriate, theprocedure returns to the locus selection (sign a2 indicated in FIG. 24).When it is appropriate, the operation to keep the corrected andregulated output table are performed and completed.

As mentioned above, in embodiment 10, various elements for makingcomplicated operations such as preparation, correction and regulation ofthe output table easily understandable are prepared, and the effect ofthe changed part of the table on the image is clearly understood, andorientation of color regulation can be given.

In embodiment 10, the pre-regulation image indication element A7 and thepost-regulation image indication element A8 are arranged on the sameoutput device as the regulation instruction element group (A1-A6,A9-A11), but they may be arranged on a different output device withsimilar effect as that in embodiment 10, and various output devices canbe prepared, corrected and regulated and the workability is alsoimproved.

In addition, the pre-regulation image indication element A7 and thepost-regulation image indication element A8 may be arranged on aplurality of output devices so as to perform correction and regulationtaking into consideration the differences in the output devices. Similareffects to that of embodiment 10 are obtained, together with the effectthat the output device across the output devices can be prepared,corrected and regulated while checking a plurality of devices at thesame time.

Industrial Applicability

As mentioned above, in the present invention, color interpolation can beperformed along the locus of the color change of the input signal bydividing the color space of the input signal into the blocks to surelyinclude the locus changing from black to white passing through thecenter part based on the chromatic locus and the achromatic locuschanging from black to white surrounding the color region capable ofhandling the input image equipment, and at the same time, the achromaticpart present in the center part of the color space can be handledseparately from the chromatic part present in the peripheral part of thecolor space, and moreover, gradation of each locus can be handledseparately, and the color control of the system to handle the colorimage equipment is facilitated.

What is claimed is:
 1. A color correction device which converts an inputsignal from a first signal coordinate system to a second coordinatesystem, comprising: an input block judging means which selects a blockof divided input space corresponding to an input signal system to whichthe input signal belongs; an input block internal position calculatingmeans calculating a position in the block selected by said input blockjudging means at which the input signal is located; an output tablereferring means obtaining from an output table a value of each apex of ablock in an output space corresponding to the block selected by saidinput block judging means; and an output signal generating meansgenerating an output signal using the value of each apex of the block inthe output space obtained by said output table referring means and theinternal position obtained by said input block internal positioncalculating means; wherein the divided input space is divided atdivision points of each locus of an achromatic color present in a centerpart of a color region and a plurality of chromatic colors present in aperipheral part of the color region, and includes divided blocks inwhich gradation in the lightness direction for each locus is separated,said input block judging means and selects the block in which the inputsignal is judged to be inside every plane of the divided block.
 2. Thecolor correction device according to claim 1, wherein said output tablereferring device includes a table prepared with a scanned value of eachof a plurality of color patches corresponding to locus division pointnumbers numbered sequentially from black to white along each locus as acoordinate value of an input division point and a colorimetered value ofeach color patch as a coordinate value of an output division point assaid output table, and said output table referring device performs colorregulation and control by changing and correcting either of saidcoordinate value of the input division point or said coordinate value ofthe output division point.
 3. The color correction device according toclaim 1, wherein said divided input space is divided into blocks whicheach include a locus changing from black to white through a center partof the color region based on chromatic loci changing from black to whitesurrounding a color region and an achromatic locus changing from blackto white through the center part of the color region, said output tablereferring means is provided with a first output table for converting asignal to be converted with a coordinate value of an input divisionpoint comprising a device value and a coordinate value of an outputdivision point comprising a standard color space value into a signal ofthe standard color space, and a second output table for converting asignal of the standard color space with the coordinate value of theinput division point comprising the standard color space value and thecoordinate value of the output division point comprising the devicevalue into a signal of the device color space as said output table, andsaid output table referring means is capable of converting a signal ofone device to a signal of another device using the standardized colorconversion of said first output table and then, using the individualizedcolor conversion of said second output table.
 4. The color correctiondevice according to claim 1, wherein said input space is divided intotetrahedrons, each including division points on the achromatic locuschanging from black to white through the center part of at least onecolor region, said output table referring means is provided with a firstoutput table for converting a signal to be converted with a coordinatevalue of an input division point comprising a device value and acoordinate value of an output division point comprising a standard colorspace value into a signal of the standard color space, and a secondoutput table for converting a signal of the standard color space withthe coordinate value of the input division point comprising the standardcolor space value and the coordinate value of the output division pointcomprising the device value into a signal of the device color space assaid output table, and said output table referring means is capable ofconverting a signal of one device to a signal of another device usingthe standardized color conversion of said first output table and then,using the individualized color conversion of said second output table.5. The color correction device according to claim 1, wherein saiddivided input space is a color region divided based on a plurality ofchromatic loci changing from black to white having different saturationlevels, said output table referring means is provided with a firstoutput table for converting a signal to be converted with a coordinatevalue of an input division point comprising a device value and acoordinate value of an output division point comprising a standard colorspace value into a signal of the standard color space, and a secondoutput table for converting a signal of the standard color space withthe coordinate value of the input division point comprising the standardcolor space value and the coordinate value of the output division pointcomprising the device value into a signal of the device color space assaid output table, and said output table referring means is capable ofconverting a signal of one device to a signal of another device usingthe standardized color conversion of said first output table and then,using the individualized color conversion of said second output table.6. The color correction device according to claim 1, wherein saiddivided input space is a color region divided based on a plurality ofchromatic loci changing from black to white and having differentsaturation levels, and includes tetrahedron-shaped blocks, said outputtable referring means is provided with a first output table forconverting a signal to be converted with a coordinate value of an inputdivision point comprising a device value and a coordinate value of anoutput division point comprising a standard color space value into asignal of the standard color space, and a second output table forconverting a signal of the standard color space with the coordinatevalue of the input division point comprising the standard color spacevalue and the coordinate value of the output division point comprisingthe device value into a signal of the device color space as said outputtable, and said output table referring means is capable of converting asignal of one device to a signal of another device using thestandardized color conversion of said first output table and then, usingthe individualized color conversion of said second output table.
 7. Thecolor correction device according to claim 1, wherein said divided inputspace is a color region divided based on a plurality of chromatic locichanging from black to white and having different hue levels, saidoutput table referring means is provided with a first output table forconverting a signal to be converted with a coordinate value of an inputdivision point comprising a device value and a coordinate value of anoutput division point comprising a standard color space value into asignal of the standard color space, and a second output table forconverting a signal of the standard color space with the coordinatevalue of the input division point comprising the standard color spacevalue and the coordinate value of the output division point comprisingthe device value into a signal of the device color space as said outputtable, and said output table referring means is capable of converting asignal of one device to a signal of another device using thestandardized color conversion of said first output table and then, usingthe individualized color conversion of said second output table.
 8. Thecolor correction device according to claim 1, wherein the selected blockis divided by a conical body having the input signal as the apex, saidinput block internal position calculating means sets the internalposition based on the volume of said conical body, and obtains theinternal position from the ratio of the volume of the divided block todiagonal block, said output table referring means is provided with afirst output table for converting a signal to be converted with acoordinate value of an input division point comprising a device valueand a coordinate value of an output division point comprising a standardcolor space value into a signal of the standard color space, and asecond output table for converting a signal of the standard color spacewith the coordinate value of the input division point comprising thestandard color space value and the coordinate value of the outputdivision point comprising the device value into a signal of the devicecolor space as said output table, and said output table referring meansis capable of converting a signal of one device to a signal of anotherdevice using the standardized color conversion of said first outputtable and then, using the individualized color conversion of said secondoutput table.
 9. The color correction device according to claim 1,wherein said output table referring means is provided with a firstoutput table for converting a signal to be converted with a coordinatevalue of an input division point comprising a device value and acoordinate value of an output division point comprising a standard colorspace value into a signal of the standard color space, and a secondoutput table for converting a signal of the standard color space withthe coordinate value of the input division point comprising the standardcolor space value and the coordinate value of the output division pointcomprising the device value into a signal of the device color space assaid output table, and said output table referring means is capable ofconverting a signal of one device to a signal of another device usingthe standardized color conversion of said first output table and then,using the individualized color conversion of said second output table.10. A color correction device which changes an input signal to beinputted as image data from a first signal coordinate system to a secondsignal coordinate system, comprising: an input block judging meansselecting a block from a divided input space representing an inputsignal system, the input space being divided into blocks comprisinglattices divided with equal intervals for each of a plurality of inputsignal components, said input block judging means selecting the blockwhere each component of the input signal is divided by a common divisorof each component and which is divided using an integer part of aquotient, said input block judging means outputting the selected blocknumber and a decimal part of said quotient; an output table referringmeans which has an output table for rapid processing where a coordinatevalue of each apex of a block in an output space which corresponds tothe block number is stored, and obtains the coordinate value of eachapex of the block in the output space corresponding to the block numberselected by said input block judging means by referring to said outputtable for rapid processing; and an output signal generating meansobtaining the output signal using the decimal part of said quotient theoutput from said input block judging means and the coordinate valueoutput from said output table referring means.
 11. A color correctionmethod which converts an input signal to be inputted as image data froma first signal coordinate system to a second coordinate system,comprising: selecting a block of divided input space corresponding to aninput signal system to which the input signal belongs; calculating atwhich internal position in the block selected by said selecting step theinput signal is located; referring to an output table to obtain a valueof each apex of a block in an output space corresponding to the blockselected by said selecting step; and generating an output signal usingthe value of each apex of the block in the output space obtained byreferring to the output table and the internal position obtained by saidcalculating step; wherein said input space is divided at division pointsof each locus of achromatic color present in a center part of a colorregion and a plurality of chromatic colors present in a peripheral partof the color region, and includes divided blocks in which gradationlevel in a lightness direction for each locus is separated, and saidselecting step selects the block in which the input signal is judged tobe inside every plane of the block.
 12. The color correction methodaccording to claim 11, wherein said step of referring to the outputtable performs color regulation and control by changing and correctingeither of a coordinate value of the input division point or a coordinatevalue of the output division point of the output table, said outputtable having been prepared with a scanned value of each of a pluralityof color patches corresponding respectively to locus division pointnumbers numbered sequentially from black to white of each locus as acoordinate value of an input division point and a colorimetered value ofeach of the plurality of color patches as a coordinate value of anoutput division point.
 13. The color correction method according toclaim 11, wherein said divided input space is divided into blocks whicheach include a locus changing from black to white through a center partof the color region and are divided based on chromatic loci changingfrom black to white surrounding the color region and an achromatic locuschanging from black to white through the center part of the colorregion, said output table referring means is provided with a firstoutput table for converting a signal to be converted with a coordinatevalue of an input division point comprising a device value and acoordinate value of an output division point comprising a standard colorspace value into a signal of the standard color space, and a secondoutput table for converting a signal of the standard color space withthe coordinate value of the input division point comprising the standardcolor space value and the coordinate value of the output division pointcomprising the device value into a signal of the device color space assaid output table, and said output table referring means is capable ofconverting a signal of one device to a signal of another device usingthe standardized color conversion of said first output table and then,using the individualized color conversion of said second output table.14. The color correction method according to claim 11, wherein saiddivided input space is divided into tetrahedron blocks includingdivision points on an achromatic locus changing from black to whitethrough a center part of at least one color region, said output tablereferring means is provided with a first output table for converting asignal to be converted with a coordinate value of an input divisionpoint comprising a device value and a coordinate value of an outputdivision point comprising a standard color space value into a signal ofthe standard color space, and a second output table for converting asignal of the standard color space with the coordinate value of theinput division point comprising the standard color space value and thecoordinate value of the output division point comprising the devicevalue into a signal of the device color space as said output table, andsaid output table referring means is capable of converting a signal ofone device to a signal of another device using the standardized colorconversion of said first output table and then, using the individualizedcolor conversion of said second output table.
 15. A color correctionapplication device which corrects and regulates color by preparing anoutput table and changing the content of the output table, said colorcorrection application device having an output table preparing device,comprising: a pre-regulation image indicating means indicating apre-regulation image; a table locus selecting means selecting anachromatic locus and a chromatic locus of the image; a table divisionpoint selecting means selecting a division point to be corrected andregulated among division points of the locus selected by said tablelocus selecting means; an effect checking image indicating meansobtaining a color region to be affected by correction and regulation byobtaining an input coordinate value included in a plurality of inputblocks to which a locus value and a division point value for the locusand division point selected by said table locus selecting means and saidtable division point selecting means respectively belong, and indicatingan image part belonging to the color region; a table data editing meansediting the coordinate value of the input division point and thecoordinate value of the output division point of the output table withthe scanned value of each color patch corresponding to the number of thelocus division point to be sequentially numbered from black to white ofeach locus for said color region as the coordinate value of the inputdivision point and the colorimetered value of each color patch as thecoordinate value of the output division point along the lightnessdirection, the saturation direction and the hue direction correspondingto the achromatic locus and the chromatic locus of the image; a keepingmeans keeping the output table to be corrected and regulated by saidtable data editing means; and a post-regulation image indicating meansconverting the pre-regulation image using the output table to becorrected and regulated by said table data editing means and indicatethe post-regulation image.
 16. The color correction application deviceaccording to claim 15, wherein said pre-regulation image indicatingmeans and said post-regulation image indicating means are arranged ondifferent output devices.
 17. The color correction application deviceaccording to claim 15, wherein said pre-regulation image indicatingmeans and said post-regulation image indicating means are arranged on aplurality of output devices.
 18. An output table preparation device,comprising: a color patch preparation means for preparing color patchesalong a locus that smoothly changes from black to white; a scanprocessing means for obtaining scanned values by scanning each colorpatch; a colorimeter processing means for obtaining colorimetered valuesfor each color patch; an output table preparing means for preparing anoutput table with the scanned values of each color patch as coordinatevalues of input division points and the colorimetered values ascoordinate values of output division points; a common divisorcalculating means for obtaining a common divisor for each component ofan input signal of said output table; a lattice forming means fordividing input signal space by each common divisor, thereby forminglattices divided with equal intervals for each component; and an outputtable for rapid processing preparation means for obtaining outputsignals corresponding to input signals as coordinate value of everylattice point, thereby preparing an output table for rapid processing.